Apparatus for removing wood waste



Nov. 6; 1951 c. v. ANDERSON A 2,574,161

APPARATUS FOR REMOVING WOOD WASTE Filed NOVv 21, 1949 FIE. l

IN V EN TOR.

CHARLES V A/msgsow ATTORNEY Patented Nov. 6 1951 UNITED STATES PATENT OFFICE APPARATUS FOR REMOVING WOOD WASTE Charles V. Anderson, Seattle, Wash., assignor to Anderson Blow-Pipe and Manufacturing Company, a corporation of Washington Application November 21, 1949, Serial No. 128,660

3 Claims. 1

This invention relates to devices for increasing and regulating degrees of suction, and particularly suction for removing waste matter from wood working machines.

In manufacturing and finishing lumber and wood products, a relatively large amount of saw dust, shavings, and other particles forming waste matter are released and which must be constantly removed. The removal is most economically accomplished by relatively large tubes into which the waste matter is drawn by air suction and thence carried away and discharged. Such suction is preferably supplied by relatively large fans connected to the tubes at a suitable distance back from the mouths, or receiving ends thereof, and driven by ordinary electric motors adapted for rotating the fans at uniform speeds to remove the normal amounts of Waste as formed.

In practice however the amounts of waste being formed frequently vary and when more than normal amounts enter the tubes their passage is slowed up or retarded and the waste accumulates or clogs the tubes, and it is necessary to increase the suction to meet the increased load. It is therefore an object of this invention to provide means for increasing the suction through the tube for drawing in and driving away all and increased amounts of waste without changing the speed of the fan.

A particular object is to provide means for releasing a portion of the air pressure from behind the fan to prevent back pressure in the tube, and thereby to increase the suction effects in front of the fan for drawing in and driving away all waste material formed.

A further particular object is to provide a doorway or outlet in the top of the chamber behind the fan for diverting such portions of the air as may exert a back pressure in the tube and to provide a plurality of relatively short baflie plates or dampers pivotally mounted across the doorway for closing the same for normal loads of Waste, together with a lever pivotally connected with the dampers for elevating the plates for increasing the suction for greater loads, and for retaining the dampers in opened and closed positions alternately.

With these and other objects to be hereinafter stated, I have illustratively exemplified my invention by the accompanying drawings, of which:

Figure 1 is a side elevation, with parts broken away, and showing the dampers in open positions. Figure 2 is a top plan taken on line 2-2 of Fig. 1,

but showing the dampers in closed positions. Figure 3 is an enlarged fragmentary detail view of the rear side of the chamber behind the fan, showing the dampers in closed positions, together with means for turning the dampers, and Figure 4 is an enlarged fragmentary detail view taken on line 4'4 of Fig. 3, showing connections of lever for operating the dampers.

Like characters on the difierent figures represent like parts. Numeral 5 represents a housing, in which is mounted a fan 6 on a shaft 1. The shaft and fan are rotatedclockwise by a conventional electric motor 8, to provide uniform air power. The blades 9 of the fan may be connected by a band II] along the outer portions thereof for rigidity. Attached to one side of the housing is a tube I I which is extended forwardly to any point required for receiving and gathering Wood Waste of various weightssuch as saw dust, shavings, etc, to be drawn into the housing by suction created by the fan. Extended rearwardly from the housing is a chamber A, having side walls I2 and I2 attached by flanges I3 to the housing. A discharge pipe I4 of suitable dimensions is connected to the rear end of the chamber as by flanges I5 and extended to any desired locationfor dischar e of the waste by air pressure from behind the fan.

When the supply of waste is normal the suction in the tube and pressure in the chamber and pipe from the uniform velocity of the fan is adapted to carry the waste as fast as the same is collected in the mouth of the tube; but when the amount of waste is increased above normal, it becomes necessary to increase the suction in the tube to overcome the weight ofthe loads inthe tube and back pressure from the loads in the chamber and discharge pipe. To provide such increased suction in front without increasing the velocity of the fan, it is necessary to decrease the back pressure behind the fan, and I accomplish this by application of any number of damper plates pivotally mounted across the otherwise open area or doorway over the upper portion of the chamber. Said plates to be regulated by a hand lever I6, and bar ll, connected together by pivot pin I8.

The damper plates are indicated by the letters a, b, c, d, and e, and are connected operatively to the bar by links 1, g, h, and i and pivots p, and by the upper end of the lever n. The damper plates are supported by attachment to rods 7, 70, Z, m, and I9, all of which rods are extended across the doorway horizontally and pivotally through the side Walls I2 and I2 and outside bearing bosses 0. It will be understood that the rod I9 is attached to the upper end n of the lever for shifting the positions of the damper plate 0.

The dampers are preferably extended laterally from the links on obtuse angles thereto and are of suitable width combined to substantially enclose the doorway when disposed horizontally as seen in Figs. 2 and 3, when the lever is drawn diagonally below the bar, for use under normal loads of waste. But when it becomes necessary to divert a portion of the air from the chamber in front of the pipe to decrease the back pressure and for increasing the suction in the tube, the lever is shifted to vertical position as shown in dotted lines Fig. 3, whereby the damper plates are inclined obliquely to provide open spaces between them to compel escape of the back pressure as indicated by the positions shown in Fig. 2. As the damper plates arepreferably supported on a plane above the top of the discharge pipe, the heaviest portions of the waste and most of the lighter portions follow a level line of travel from the base of the housing into the pipe, but any of the lighter portions which escape between the dampers may be carried away by any discharge outlet as 20.

In order to guide and retain the lever in any desired position, for maintaining the damper plates in suitable positions, a bracket 2| is extended from the wall [2' on which is supported a quadrant 22, provided with a slot 23, in which a bolt 24 is slidably disposed and thence through the lever, and may be latched in any desired angle by a nut 25. By experiments and practice, I have discovered that a single damper used alone would have to be so wide that it would project down into the waste in lower portion of the chamber, but a plurality of relatively narrow plates having their fronts tipped downward diagonally will scoop .up and divert suflicient of the upper portions of the currents, without retarding the waste or diverting the latter from travel into and from the pipe.

Having described my invention, I claim as new for Letters Patent:

1. An apparatus for removing wood waste, comprising, a chamber horizontally disposed and discharge pipe from one end thereof for passage of wood waste therethrough under air pressure being provided with a doorway across the top portion thereof above the level of the top of the pipe for the escape of portions of the air above the waste, means for normally closing the doorway, and for regulating the escape of the air including a plurality of relatively short damper plates mounted on pivots across the doorway, links affixed to one of the ends of the pivots and exfro for opening and closing the damper plates and for retaining the plates in such opened and closed position respectively.

2. In an apparatus for regulating pressure in a horizontally disposed chamber and discharge pipe, said chamber being normally open across its upper part for a doorway, a plurality of relatively short damper plates pivotally mounted from their rear edges across said doorway for normally closing the doorway, a lever operatively connected with the damper plates for turning the same diagonally into spaced relation from each other to provide scoops to divert a portion of the air in the chamber and to increase the flow of the waste through the lower portion of the chamber into the pipe, and to prevent back pressure from the chamber against flow of waste into the same.

3. An apparatus for removing wood waste under air pressure, including a chamber and pipe horizontally disposed for discharging the waste therethrough, in combination with means for varying the pressure, the said chamber having a doorway over the top thereof, rods pivotally disposed through the sides of the chamber and extended across the doorway, a plurality of relatively short damper plates attached to the fronts of the rods for closing the doorway, a connecting bar horizontally disposed on one side of the chamber, links attached to one of the ends of the rods and pivotally connected with the bar, for opening and closing the damper plates over the doorway for varying pressure in the chamber and pipe, and a lever for shifting the bar to and fro for actuating the links and turning the fronts of the dampers diagonally for scoops for skimming portions of the air from the top portion of the chamber above the flow of waste beneath.

CHARLES V. ANDERSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,017,509 Callan Feb. 13, 1912 1,281,216 Schellens Oct. 8, 1918 1,818,367 Wallace Aug. 11, 1931 

